Is Len Sassaman Satoshi Nakamoto? The quest to unmask Bitcoin's creator

Crypto's longest-standing mystery is surely the true identity of Satoshi Nakamoto — the pseudonymous creator of Bitcoin and the individual or group that set the modern crypto machine in motion. Many have set out to identify Nakamoto, while others have claimed to be the person behind crypto's pioneering asset. It's a mystery that remains to this day, fueled by speculation, legal wrangling, and the growing interest in crypto at large.

One of the most intriguing names put forward as Bitcoin's creator is Len Sassaman. The late American cryptography expert was thrust back into the spotlight during October 2024 following the release of a HBO documentary that claimed to reveal Sassaman as Nakamoto. In reality, their identity remains a mystery. Still, the evidence surrounding Sassaman deserves attention. In this article, we'll explore who Len Sassaman is and look at the evidence behind claims that he is Satoshi Nakamoto.

Who is Satoshi Nakamoto?

It's worthwhile to first understand who Satoshi Nakamoto is. The name is considered a pseudonym because the true identity of Bitcoin's creator or creators has never conclusively been revealed. Nakamoto chose to remain anonymous throughout their active years before disappearing in April 2011.

Nakamoto authored the landmark Bitcoin whitepaper published in October 2008, which set out the framework for the first usable digital currency built upon blockchain technology. Significantly, Nakamoto is credited with solving the "double spending" issue that held back earlier forms of digital currency by developing a peer-to-peer distributed timestamp server.

The Bitcoin network would launch in January 2009, and Nakamoto remained a prominent figure in its development until their disappearance in 2011. Nakamoto holds the first Bitcoin address created, which is estimated to hold between 600,000 and 1.1 million BTC. At Bitcoin's all-time high price, Nakamoto's BTC holdings could have been worth approximately $75.67 billion.

Who is Len Sassaman?

Born in Pennsylvania, U.S.A, in April 1980, Len Sassaman had an early start in cryptography and computer privacy. Sassaman reportedly moved to San Francisco during his late teens and joined the cypherpunks community, a movement closely tied to the inception of Bitcoin. Cypherpunks believed in personal privacy, individual freedom, and protection from censorship, and were born out of a desire to resist growing government surveillance seen during the 1980s.

Aged just 18, Sassaman was a member of the Internet Engineering Task Force (IETF), founded in 1986 to set the technical standards underpinning the internet. He co-authored the Zimmermann–Sassaman key-signing protocol in 2005 that aimed to accelerate the public key fingerprint verification task during a key signing party. The protocol can be likened to modern cryptographic methods used today to establish trust in decentralized systems.

Sassaman would go on to be a senior systems engineer for internet privacy company Anonymizer, and a PhD candidate at Belgium's Katholieke Universiteit Leuven. Here, Sassaman contributed to research efforts within the university’s Computer Security and Industrial Cryptography (COSIC) group. The cryptographer also regularly appeared at the DEF CON hacker convention, becoming a prominent figure in the community.

Sassaman passed away in July 2011.

What's the evidence for Sassaman being Nakamoto?

Many would agree that the evidence in favor of Sassaman being the real Nakamoto is intriguing. Let's take a closer look.

He was an early cryptographic expert

Perhaps the most compelling piece of evidence is Sassaman's early cryptographic work. His teenage years spent on the Internet Engineering Task Force likely helped give Sassaman a solid technical foundation. Meanwhile, later on, Sassaman was the maintainer for the Mixmaster anonymous remailer code, working alongside cryptography pioneer David Chaum. Remailer technology is considered to be a precursor to Bitcoin's technology due to its use of decentralized nodes. Add to this Sassaman's status as an early member of the cypherpunk community, and it's understandable why many consider him to be a strong candidate for Satoshi Nakamoto.

He was connected to other early cryptographic pioneers

Alongside Sassaman's collaboration with Chaum, the late American was also well-connected to other influential figures that helped lay the groundwork for the blockchain-based networks we see today. After moving to San Francisco in 1999, Sassaman lived with Bram Cohen, the author of the BitTorrent peer-to-peer protocol. Sassaman also reportedly worked alongside computer scientist Hal Finney — another figure put forward as potentially being Nakamoto. Meanwhile, Sassaman's work with Phil Zimmermann on the Zimmermann–Sassaman key-signing protocol is already well-publicized.

Moving in these circles would have given Sassaman access to other forward-thinking cryptographic minds with the skills and motivation to help drive forward the Bitcoin project.

Coincidences in Nakamoto's disappearance

Another piece of evidence many commentators point to is the alignment of Satoshi Nakamoto's last public communications and Sassaman's passing. The final message shared by Nakamoto in April 2011 revealed "I've moved on to other things." Just three months later, Sassaman passed away. Although these events can be put down to coincidence, many still point to their timing as further evidence of Nakamoto's true identity.

Why the need to unmask Nakamoto?

The Bitcoin network has successfully navigated four halving events and the meteoric rise of the Bitcoin price since its 2009 inception. Major upgrades such as SegWit, Taproot, and the Lightning Network have also enabled Bitcoin to scale, enhance privacy, and optimize transaction throughput — all seemingly without Nakamoto's involvement. Bitcoin ordinals also arrived in 2023 to allow non-fungible tokens to be inscribed on Satoshi's — the smallest unit of Bitcoin measurement. Meanwhile, plenty of Bitcoin DeFi projects, one of the most recent ones being Fractal Bitcoin, have been built either on top of or around Bitcoin, without compromising its security or decentralized nature. With over a decade of independent development, Bitcoin’s decentralized nature thrives without needing to unmask its creator.

Many agree that it's unnecessary to unmask Nakamoto, and at odds with the values Bitcoin was founded on — namely privacy. Regardless, the crypto community seems confident that Nakamoto's identity will remain unknown into 2025. According to Polymarket, there's just an 8.8% chance Nakamoto's identity will be proven during 2024.

Source: polymarket.com

The final word

The debate around Satoshi Nakamoto's identity is likely to continue, even following the HBO documentary claiming Len Sassaman to be the Bitcoin creator. Although Sassaman undoubtedly played an influential role in moving forward the development of computer privacy and cryptographic methods right up until his passing in 2011, it remains impossible to confirm whether he's the man responsible for crypto's first and largest asset.

For many, the technology and its contribution to creating a more equitable financial future are more important than the person or people behind its inception.